This study gives great insights into the formation of sanukitoid magmas using Ti isotopes, but a few things could use more clarification. First, since the study supports a fluid-fluxed eclogite melting model, could the authors explain how temperature changes and pressure-related phase equilibria might have affected Ti isotope fractionation? Since rutile stability is key to this process, were any high-pressure experimental constraints considered to confirm its role under Archean conditions?
Also, the paper compares sanukitoid differentiation trends to modern calc-alkaline suites, but was crustal contamination taken into account? Given that the samples come from different cratonic settings with varying lithospheric compositions, a discussion on how crustal assimilation might have influenced the Ti isotope record would make the interpretations even stronger.
I previously came across a comment on this study regarding the effects of temperature changes and pressure-related phase equilibria on Ti isotope fractionation. The comment also questioned whether high-pressure experimental constraints were considered to confirm rutile stability under Archean conditions. Upon reviewing the paper again, I see that the study does discuss the role of rutile in Ti fractionation but does not seem to incorporate direct high-pressure experimental data to validate its stability. Could the authors clarify if any such experimental constraints were considered or if the interpretations are based solely on natural samples and theoretical modeling?
Additionally, the comment raised a concern about potential crustal contamination influencing the Ti isotope record. From my understanding, the study accounts for lithospheric variations but does not explicitly quantify crustal assimilation. If I’m mistaken, could the authors point to where this aspect is addressed? A more detailed discussion on how contamination was assessed could strengthen the interpretations.